Process of making formylmethylanthranilic acid.



NITED STATES PATENT OFFICE.

FRIEDRICH VON BOLZANQOF HOCHST ON-THE-MAIN, GERMANY, ASSIGNOR TO FARBWERKE, VORM. MEISTER, LUOIUS & BRIININ THE-MAIN, GERMANY, A CORPORATION.

PROCESS OF MAKING FORMYLMETHYLANTHRANILIC ACID.

SPEGIFICATIONforming part of Letters Patent No. 712,246, dated October 28, 1902.

Application filed May 13, 1902. Serial No. 107,072. (No specimens.)

/\ coon l The oxidation occurs in an aqueous solution with manganates or permanganates of alkalies or alkaline earths. To obtain good yields, it is preferable to neutralize the free alkali and alkali carbonate formed on oxidation. This is effected by successively adding to the liquid undergoing oxidation an acid or,

better, magnesium sulfate.

My invention relates to the manufacture of formylmethylanthranilic acid by the foregoing oxidation.

The following example illustrates the process: One hundred kilos of chlorlnethylate of quinolin or the equivalent proportion of brommethylate of quinolin and one hundred and eighty-five kilos of crystallized magnesium o sulfate are .dissolved together in water. Into this solution is run with rapid stirringa cold saturated solution of two hundred and ninetyfive kilos of potassium permanganate or the equivalent proportion of another permanganate or manganate. The oxidation being completed, the precipitated manganese oxid and magnesium hydroxid are filtered. The filtrate is treated with sixty to sixty-five kilos of hydrochloric acid of 20 Baum specific gravity and concentrated at water-bath temperature. On cooling formylmethylanthranilic acid crystallizes.

In the above example the magnesium sulfate may be omitted; but it will then be nec essary to add more hydrochloric acid, about one hundred and forty to one hundred and forty-five kilos of 20 Baum specific gravity, to the liquid filtered from the manganese. The yield of formylmethylanthranilic acid by the second method is generally somewhat inferior.

The formylmethylanthranilic acid crystalizes from water in feebly-yellowish prisms having the odor of coumarin and melting at 167 centigrade. It is readily soluble .in alcohol, little soluble in cold but more abundantly in hot water. When boiled with dilute alkalies, formylmethylanthranilic acid loses its formyl group and yields the wellknown methylanthranilic acid,which melts at 177 centigrade.. I

Formylmethylanthranilic acid may serve G, OF HocHs -oN- as parent material for the manufacture of indigo.

Having now described my, invention, What I claim is The herein -described process of making formylmethylanthranilic acid, which consists in oxidizing halogenmethylates of quinolin in an aqueous solution,substantially as set forth.

In testimony that I claim the foregoing as my invention I have signed my name in presence of two subscribing witnesses.

FRIEDRICH VON BOLZANO.

Witnesses:

ALFRED BRISBOIS, J OHANN HARTENSTEIN. 

